In the related art, for example, a vehicle sun roof apparatus as disclosed in JP 2000-108676A (Reference 1) (a so-called outer slide sun roof) is known. In this apparatus, a link mechanism configured to support a movable panel includes a rear lift link configured to perform the swinging motion by a sliding motion of a first shoe, a front lift link configured to perform a swinging motion by a sliding motion of a second shoe, and a connecting rod configured to couple the rear lift link and the second shoe and cause the second shoe to perform a sliding motion by the swinging motion of the rear lift link. When the first shoe is caused to perform the sliding motion, the rear lift link performs a swinging motion and lifts a rear end of the movable panel, and in this process, the swinging motion of the rear lift link is transmitted to the second shoe via the connecting rod. By the sliding motion of the second shoe in association therewith, the front lift link is caused to perform the swinging motion so as to lift a front end of the movable panel. With the operation as described above, the movable panel is tilted up.
Subsequently, by causing the first shoe and the second shoe to slide, the movable panel slides outward in a state of being tilted up and brings an opening section formed in a roof panel into an opened state. In this case, since the rear lift link is brought into the swinging motion by the effect of an engagement structure set between the rear lift link and the first shoe, a tilt-up motion of the movable panel may be performed slowly by the setting of the engagement structure.
In the vehicle sun roof apparatus of JP 2000-108676A, the amount of movement (operation stroke) of the first shoe or the like required until the movable panel reaches the fully-opened state from the fully-closed state corresponds to the amount of movement of the first shoe or the like from the fully-closed state→tilt-up state→fully-opened state. Therefore, when the amount of movement of the first shoe or the like until the movable panel moves from the fully-closed state to the tilt-up state (hereinafter, referred to also as “tilt operation stroke”) increases, securement of the amount of movement of the first shoe or the like until the movable panel moves to the fully-opened state, that is, the amount of opening of the movable panel becomes difficult.
In contrast, since the tilt operation stroke corresponds to a segment of a high-load state during which the movable panel moves upward and downward, it is preferable to secure the tilt operation stroke as long as possible. When it is assumed that the tilt operation stroke is reduced, a load per unit operation stroke increases, and the size of an electric power source (motor or the like) for driving the first shoe or the like needs to be increased correspondingly.
In the vehicle sun roof apparatus (outer slide sun roof) disclosed in Japanese Patent No. 4109583 (Reference 2), a guide rail projecting toward the front so that the guide rail that allows a shoe to slide therein penetrates through a front frame (housing) is proposed. Accordingly, for example, a supporting span of the movable panel may be widened while increasing the amount of opening of the movable panel, or without impairing the amount of opening of the movable panel.
However, an effect of increase of the amount of opening of the movable panel by providing the guide rail so as to penetrate through the front frame is insignificant, and the securement of the amount of opening is still difficult.
A need thus exists for a vehicle sun roof apparatus which is not susceptible to the drawback mentioned above.